1. Field of the Invention
The present invention relates to a printing apparatus and control method.
2. Description of the Related Art
A conveying mechanism including a plurality of rollers is known as a conveying mechanism for a printing medium (for example, paper) in a printing apparatus such as a printer, copying machine, or facsimile apparatus. A conveying mechanism of this type includes, for example, a feeding roller, conveying roller, and discharging roller. The feeding roller conveys, for example, a stacked printing medium to the conveying roller. The conveying roller conveys a printing medium during, for example, printing of an image. The discharging roller conveys, for example, a printing medium on which an image has been printed, and discharges it from the apparatus. The feeding roller and conveying roller are sometimes used for skew correction of a printing medium. In skew correction, for example, the leading end of a printing medium is abutted against the conveying roller by conveyance by the feeding roller so that the leading end of the printing medium uniformly abuts against the conveying roller in the whole region.
To increase the total printing speed when continuously performing a printing operation on printing media of a plurality of pages, the timing to start the feeding operation of a subsequent printing medium (of the next page) is preferably as early as possible after the end of a printing operation for a preceding page. However, an excessively early feeding start timing sometimes causes trouble.
Japanese Patent Laid-Open No. 2001-310833 has proposed an apparatus which changes the feeding start timing of a subsequent printing medium based on a margin amount from the leading end of the subsequent printing medium to a printing start position. When continuously performing the printing operation on printing media of a plurality of pages, this apparatus can shorten the total printing time.
The apparatus in Japanese Patent Laid-Open No. 2001-310833 includes a motor for driving a feeding roller, and a motor for driving a conveying roller and discharging roller. That is, this apparatus includes two roller driving sources. Since control of the feeding roller and control of the conveying roller and discharging roller can be performed by the separate driving sources, this has functional advantages such as skew correction and control of the feeding start timing. However, since the two driving sources are arranged, there is room for improvement in cost. If the number of driving sources can be decreased to one, this has an advantage in cost. In addition, if skew correction and control of the feeding start timing can be performed using one driving source, the functional advantages are also maintained in addition to the cost advantage.